In order to facilitate Projects 2,3,4, and 5, and animal core laboratory has been established to do the following: provide a well-defined animal model of brain injury which produces nonfatal, focal and reproducible injury resulting in a histopathological picture similar to the clinical condition: handle and process all experimental and control animals for the experimenters; perform all surgeries on the animals under the most careful of conditions; perform tests of sensory-perceptual and motor functioning on the animals; perform behavior assessment of cognitive functions on the animals; and process tissue for histological tests. Non-penetrating, localized deformation of the cortex has been the mouse successful and extensively used rodent model. We will employ an electronically-controlled pneumatic impactor to achieve a closely controlled strike of the brain's cortical surface, in a fully anesthetized animal. This device produces precisely controlled brain contusions which are reproducible and which resemble many of the aspects of closed head injury seen clinically.